The quad rotorcraft has a multivariable, strongly coupled, complex and nonlinear system. Due to moving in a three dimensional space, it is more difficult to control its flight attitude and movement track than a robot on the ground. Limited by the limited load capacity and power supply, the compact rotorcraft senses the external environment by means of an airborne portable sensor system (such as a vision sensor, a compact laser range finder). In the meanwhile, an onboard control panel has a limited operational capability, through which operations on complex vision and control algorithm are difficult to perform, so it is a very challenging issue regarding how to sense the external environment according to the onboard compact sensor system, and how to program and control the movement track of the compact rotorcraft to realize an autonomous flight.